Latch tripping device



2 Shets-Sheet 1 INVENTOR March 8, 1955 H. w. sANFoRD LATCH TRIPPINGDEVICE Filed May 2, 1950 March 8, 1955 H. lW. SANFORD LATCH TRIPPINGDEVICE 2 Sheets-Sheet 2 Filed May 2, 1950 INVENTOR W Sanfafd ATTORNEYUnited States Patent O LATCH TRIPPING DEVICE Hugh W. Sanford, Knoxville,Tenn.

Application May 2, 1950, Serial No. 159,457

6 Claims. (Cl. 214-58) This application is a continuation-in-part of myprior applications, Serial No. 571,170, tiled January 5, 1945, nowPatent No. 2,674,383, granted April 6, 1954, and Serial No. 739,795,tiled April 7, 1947, now Patent No. 2,634,007, granted April 7, 1953.

This invention relates to improvements in Latch Tripping Devices, of thecharacter used for controlling the release of drop bottom doors ofconveyances, such as mine cars.

This is an improvement on the latch tripping mechanism set forth in myprior patent, No. 2,399,708, granted May 7, 1946. In the prior device,the latch tripping mechanism was operated by a lug on a side sill of thecar, which would require the lug to be disposed laterally of the latchhook which supports the door, and causes a somewhat more complexapparatus to be required than is desired.

One object of this invention is to simplify and improve the constructionof the latch tripping device and the manner in which it is operatedautomatically by the car, by providing for the operation of the trippingdevice directly by one of the doors, such as a lug on the bottom of thelatched door. This provides for bringing the controlling means veryclose to the point where the latch hook is located, often remote fromthe side sills of the car, in closer` relationship to the latch hook.Furthermore, if the rear end-sill structure should droop, or when thewheel treads should wear, causing the latch hook to be lowered closer tothe top of the rails, the rear door will be lowered correspondingly, andthe relationship between the tripping means and the hook will not bechanged ap- The operation of the latch tripping device directly by thelatched door itself not only provides a much simpler and less expensivemechanism that is more practical to manufacture, but also makes possiblethe supporting of the door by two laterally spaced hooks which can bebrought fairly close together on the longitudinal axis of the car,directly behind the central bumper of the endsill structure. Then if oneof the latch hooks should fail to latch, the other hook will be in amore central position and will support the load on the door nearer toits center line, without as much danger of bending of the door plate dueto the weight on the unsupported edge thereof. Moreover, if the edge ofthe door should become bent or warped, the variation in the height ofthe latch engaging elements on the door above the rail would be morenearly the same on such a bent door than it would be if these elementswere spaced farther apart transversely.

Another object of the invention is to provide for a more positiverelease of the latch hook by an arm which will jerk the hook out fromunder the free edge of the door, which tripping arm is operatedpositively by a lever arm operated by engagement with a lug orprojection on the bottom of the door. The tripping arm is pivotallysupported so that it will swing down out of tripping position in adirection toward the front of the car. Such an arm will be lowered veryrapidly after releasing the latch, so there will be no tendencywhatsoever for it to touch the end sill structure, even though the carbe running at very high speed. However, if the end sill structure shouldcontact the tripping arm, it would have the effect merely of forcing thearm down out of the path of the car, without danger to the trippingmechanism.

Gil

Patented Mar. 8, 1955 ice Still another object of the invention is toprovide greater llexibility between the operating parts of the trippingmechanism by yieldable connection therebetween, such yieldable means notonly acting on the tripping means but also yieldable means acting on thelever arm. The yieldable means acting on the lever arm allows forvariations in the height of the door above the track and also permitsbodily movement of the lever arm when the car passes over the trippingmechanism in reverse direction and the lever arm thereby contacts thedoor or the pad thereon.

According to a preferred embodiment of the invention, provision is madefor latching the drop bottom door or doors of the conveyance by means ofa latch hook which engages the rear edge of the latched door, and whichhook preferably is disposed above the lower edge of the end sill, asdescribed in my patent, No. 2,399,708, as well as above the lower edgeof the door. A tripping arm is mounted in the trackway in position to beraised into engagement with the latch hook -in properly timed relationwith the movement of the car or conveyance over the tripping device.This operation of the tripping arm preferably is accomplished by meansof a lever arm operatively connected with the tripping arm and disposedin close relation therewith, in position to be operated directly by thelatched door itself. It is preferred that the operation of the lever armbe accomplished by means of a pad provided on the bottom of the doorplate. The proportioning of the lever arm and tripping arm may be suchas to raise the tripping arm into position for engagement with the latchhook, as the car or conveyance passes over the tripping device.

It is preferred that the tripping arm be pivotally mounted in thetrackway for swinging movement toward the front of the car or conveyanceand engage the latch by a jerk-out action so as to pull the latch to areleased position as the conveyance passes over the tripping device. Alever mounted in the trackway has a yieldable connection with thetripping arm to provide for relative motion therebetween. A shoe on thelever is also yieldably supported in position for engaging a pad on thedoor to operate the tripping arm as the car passes over the trippingdevice. This shoe is thus held up in position for engaging the pad, butthe yieldable support thereof allows for variations in the height of thedoor, as Well as accommodating for reverse movement of the conveyanceover the tripping device.

The invention is illustrated in one embodiment in the accompanyingdrawings, in which:

Fig. 1 is a side elevation of a drop bottom mine car howing the improvedform of latch tripping device there- Fig. 2 is an enlarged longitudinalvertical sectional View thereof;

Fig. 3 is a cross section on the line 3--3 in Fig. 2; and

Fig. 4 is a similar view on the line 4--4 in Fig. 2.

This invention is shown as applied to a mine car of the general type setforth in my prior patent, No. 2,001,471, granted May 14, 1935, adaptedfor conveying coal or other loose lading from a receiving point to atipple or other point of discharge. The mine car is shown to be of the4-wheel type, having three drop bottom doors interconnected for releasein one-two-three order. This application of the invention is used,however, merely for purpose of illustration, and it is evident that thesubject-matter of this invention may be applied to other types of cars,vehicles, and drop bottom conveyors in general, wherever it may bedesirable to release bottom doors for dropping, in which the principlesof this invention may be applicable.

The general structure of the car illustrated comprises a car body formedof side and end walls 1 and 2 rigidly secured together, the side walls 1rising from a pair of oppositely disposed side sills 3, connectedtogether at the ends of the car by means of combined end-sills andbumpers, designated generally at 4. The side and endwhich is a bottomopening designated generally at 5 (Fig. 3) for discharge of the ladingtherethrough.

The car is supported upon wheels 6 and axles 7 connected with the sidesills 3. The wheels 6 are adapted to travel on a track formed by a pairof laterally spaced rails indicated generally at R.

Each of the doors 8, 9 and 10, usually is pivotally supported or hingedat its forward edge, capable of downward swinging movement at the pointof discharge or tipple for discharge of the lading. Each of the forwardor middle doors supports the free edge of the next forward door in theconstruction usually employed heretofore in the art, while the rear edgeof the rearward door is adapted to be latched, and, when released, willallow successive or simultaneous dropping of the doors, according to thecharacter of mountings used for the doors, various forms of which arewell-known and have been used in the art.

In the form of door supporting mechanism shown in my prior patent, No.2,001,471, three drop bottom doors were illustrated and adapted fordischarge in onetwo-three order from front to rear of the car, thepivotal mountings for the middle and rear doors permitting bodilyslidable movement thereof, Then upon release of the rearward door, itmay drop sufficiently to drag and move bodily rearward, therebyreleasing the free edge of the middle door which will likewise drop andrelease the free edge of the forward door. This occurs usually justbefore the car reaches the tipple or bin, and permits dropping of theforward door in the bin for discharge of the lading thereon, as soon asroom enough is provided in the bin therebeneath. The other doors drop insuccession during the continued forward movement of the car over the binor tipple in one-twothree order from front to rear of the car.

After dumping in passing over the bin or tipple, the doors are adaptedto be closed by the usual door-closing rails located in the track. Thedoors are thus moved successively about their hinge rods to their closedpositions, and the middle and rearward doors are pushed forward intowedging relation with the next forward door, adapted to be latched inclosed position.

As shown in Figs. 2 to 4, provision is made for latching the free edgeof the rearward door 10 in closed position, thereby holding the severaldoors closed, to retain the lading in the car until the latching meansis released for dumping. For this purpose, I have pro vided on the freeedge of the rearward door 10, one or more supporting trunnions 14, onefor each latch of said door. I prefer to use a pair of latches. eachdesignated generally by the numeral and spaced apart as indicated inFig. 2, symmetrically with respect to tg? loggitudinal center plane ofthe car, designated P Each of the latches 15 is provided with anengaging notch 16 in the forward face thereof, as hereinafter describedmore in detail. The latches 15 are pivotally mounted on a cross shaft 17supported by brackets or plates 18 secured to the adjacent end wall 2 ofthe car. Each of the latches 15 is preferably so constructed, orspring-pressed at 22, as to be disposed normally in its door-supportingposition', or to return thereto automatically when disengaged forrelease of the lading.

Each of the latches 15 is provided with a seat 19 (Fig. 2) at theforward face thereof in position to receive the end of the adjacenttrunnion 14 attached to the free edge of the rearward door 10. As shownin Fig. 2, the seat 19 is located on the opposite side of the verticalplane passing through the pivot axis of the latch 15 from the door 10,so that the Weight of the' door and the lading thereon tend to maintainthe latched relation without any tendency for this weight to push thelatch to one side. This is particularly true when a concave seat isengaged by a convex end of the trunnion, whereby any movement of thelatch tending to release the door must raise up the free edge of thedoor.

The latches 15 are interposed between the free edge of the rearward door10 and the adjacent end sill structure 4, underneath a guard plate 27,secured to the adjacent end wall 2, and which guard plate is supportedalso on the top edges of the mounting plates or brackets 18.

The latches 15 are so constructed and ,arranged that they are disposedwholly above the lower edges of the end-sills of the car, and also,preferably, above the lower face of the rearward door, in protectedpositions. This prevents disarrangement of the latches or damage theretoin the event of wreckage of the car or from contact with obstructions inthe trackway, as might occur in a mine, thus assuring adequateprotection of the latches to maintain these in proper operativepositions. Each latch 15 is so mounted in protected position between thedoor 10 and the bumper 4 that a tripping space is provided between saiddoor and the latch 15 in latched position for entry of a tripping armtherebetween.

The tripping mechanism for the latches 15 is adapted for mounting in thetrackway between the opposite rails R at a point adjacent the bin orother point of dumping. This tripping mechanism may be attached to therails R or supported thereby or otherwise in the trackway.

In the form illustrated, the tripping mechanism is shown as mounted on asupporting plate 28, rigidly secured at opposite edges thereof to thetrack rails R. This plate 28 is reinforced by bars welded on the surfacethereof.

Where two latch hooks are provided spaced on opposite sides of thelongitudinal upright central plane of the car, a tripping device may beprovided, if desired, for each such latch hook, or both hooks may beoperated by a single tripping device. It is preferred, however, thatseparate tripping devices be used. Each such tripping device may be ofthe form shown in Figs. 2 to 4, which illustrate one form of thisinvention.

In this form as illustrated, bearing boxes 30 are secured upon themounting plate 28 in a longitudinally spaced relation, and journaledtherein is a mounting pin 31. As shown in Fig. 4, the mounting pins 31are separate and in axial alignment on opposite sides of the uprightcentral plane of the conveyance, although one mounting shaft may be usedfor both tripping arms, if desired, having a single actuating levertherefor.

A tripping arm is shown at 32 mounted on each pin 31, a separatetripping arm being shown for each latch 15. This tripping arm 32 extendsupwardly forwardly of the trackway, as shown in Fig. 2, and has anengaging hook 33 in the upper end portion thereof, in position to engagein the notch 16 in the latch. The engaging hook 33 is shown as havingsubstantially a wedgeshaped end to be deected by the lower end of thelatch after releasing the latter from the door.

A separate mounting shaft is shown at 34 journaled in bearings 35 on thesupporting plate 28. This shaft is shown as extending from side to sidefor operation by one lever arm of the tripping devices for both latches.

Fixed rigidly on the shaft 34 is a connecting arm 36, one for eachtripping arm 32 and extending from the shaft 34 to a position beside thetripping arm. The connecting arm 36 is connected yieldably with thetripping arm 32 by a coiled spring 37 interposed between spring seats 38and 39 on the arms 32 and 36 respectively. A bolt 40 passes through thespring and seats to hold the same in alignment.

The upward travel of the tripping arm 32 is adapted to be limited by anadjusting bolt 41 threaded through the mounting plate 28 in position toengage a lug 42 or a side of the arm 32. The bolt 41 may be adjusted tovary the upper limit of the arm 32.

The connecting arm 36 carries a lug 43 on a side thereof having anadjusting bolt 44 passing therethrough. The lower end of the bolt 44projects in position to engage an arm 45 on a bell-crank lever 46,journaled on the shaft 34. The other arm 47 of the bell-crank lever 46extends upwardly, as shown in Fig. 2.

A contact member comprising a shoe 48 is sleeved loosely over the arm47, slidably thereon, with an interposed spring 49 between the shoe 48and the arm. The spring 49 normally urges the shoe upward but will yieldfor downward movement of the shoe thereon to accommodate an abnormallylow part of the conveyance or in the event of movement of the conveyancein a backward direction over the tripping device. A connecting bolt 50between the shoe and lever 46 limits the movement of the shoe relativethereto.

The upper end of the shoe 48 preferably is beveled at 51 in position toengage a pad 52 welded on the under face of the door or otherwisesecured thereto. The pad 52 has a long inclined forward lower edgeportion 53 and a short beveled rearward lower edge portion 54 tofacilitate engagement with the beveled end 51 of the shoe 48.

Normally the shoe 48 is held in an upright position by the weight of thetripping arm 32 pressing downward on the connecting arm 36, in partcounterbalanced by a weighted arm 55 fixed to the shaft 34.

Normally the tripping arm 32 is in lowered position, as shown in dottedlines in Fig. 2, with the lever arm shoe 48 upstanding in the path ofthe pad 52.

As the conveyance passes over the tripping device in the forwarddirection indicated by the arrow in Fig. l, the inclined face S3 of thepad 52 will strike lthe beveled end S1 of the shoe 48. This will rockthe shoe counterclockwise in Fig. 2 suiciently to allow the pad S2 topass over the shoe.

Such rocking movement of the shoe 48 will swing the lever 46, causingthe arm 45 thereof to press upward on the connecting arm 36 therebyraising the outer end of the latter. This movement of the ,connectingarm 36 will be transmitted through the spring 37 to push upward on thetripping arm 32, moving Ythe latter to the full-line position in Fig. 2.This will occur as the way is cleared over the tripping arm, the hook 33of which will be raised into the path of the latch 15. The length of thebottom face of the pad 52 is sufficient to hold the hook 33 up until itengages in the notch 16 and moves the latch to the released positionshown in dotted lines in Fig. 2.

Then the end of the shoe 48 will drop off the back end of the pad 52,releasing the pressure on the connecting arm 36, which thereby releasesthe holding action on the tripping arm 32, allowing the latter to dropby gravity. This action occurs before the end sill strikes the trippingarm and allows the latter to fall out of the path of the end sill.However, the forwardly swinging tripping arm is so mounted that, if itshould be hit by the end sill, such engagement would merely knock thearm downward without causing damage to the device.

The spring connection 37 provides a lost-motion connection between theactuating lever and the tripping arm. The spring 49 also provides ayieldable support for the shoe 48. In the event of movement of theconveyance in the reverse direction over the tripping device, thebeveled face 54 of the pad 52 would engage the upper end of the shoe 48,pressing the latter downward against the tension of the spring 49 toallow the pad to pass thereover. The two springs cooperate to providethe desired yieldability for a flexible tripping device.

The operation of the tripping device by a pad on the bottom of the doorsenables the latches to be brought in closer toward the center of thecar, and is more readily adaptable to cars of different lengths.

While the invention has been illustrated and described in oneembodiment, it is recognized that variations and changes may be madetherein lWithout departing from the invention as specified in theclaims.

I claim:

l. In conveying mechanism, the combination with a trackway, a dumpingconveyance movable along the trackway and having a drop bottom door andlatch means for holding the door closed and movable to release the doorfor opening, said latch means being mounted on the conveyance formovement lengthwise thereof and having an actuating portion with a notchin the forward face thereof, of tripping mechanism mounted at thetrackway and including a tripping member, means mounting the trippingmember in the trackway for upward swinging movement, said trippingmember being mounted on said means for lowering movement in a directiontoward the forward end of the conveyance, a contact member, lever meansoperatively connecting the contact member with the tripping member,means forming yieldable lostmotion connections between the contactmember and the lever means and between the lever means and the trippingmember, and means on the conveyance in position to engage the contactmember for operating the latter to move the-tripping member into latchengaging position.

2. In conveying mechanism, the combination with a trackway, a dumpingconveyance movable along the trackway and having a drop bottom door andlatch means for holding the door closed and movable to release the doorfor opening, said latch means being mounted on the conveyance formovement lengthwise thereof and having an actuating portion with a notchin the forward face thereof, of tripping mechanism mounted at thetrackway and including a tripping member, means mounting the trippingmember in the trackway for upward swinging movement, said trippingmember being mounted on said means for lowering movement in a directiontoward the forward end of the conveyance, a pivoted lever member, a shoeslidably mounted on the lever member, a spring interposed between thelever member and the shoe normally urging the shoe to extended positionrelative to the f lever member, a connecting arm connected with thelever member, means forming a yieldable lost-motion connection betweensaid connecting arm and the tripping member, and a pad fixed to thebottom of the door in position to engage the shoe to cause movement ofthe tripping member into operative engagement with the latch means.

3. In conveying mechanism, including a trackway adapted to receive adumping conveyance thereon having a drop bottom door and latch means forholding the door closed, the combination of tripping mechanism adaptedto be mounted at the trackway and including a tripping member, meansmounting the tripping member for upward swinging movement to engage thelatch means and for lowering movement in a direction forwardly of thetrackway, an upright contact member adapted for engagement by means onthe conveyance, lever means operatively connecting the contact memberwith the tripping member, and means forming a lost-motion yieldableconnection between said lever means and the contact member, and meansforming a lost-motion yieldable -connection between said lever means andthe tripping member.

4. In conveying mechanism, including a trackway adapted to receive adumping conveyance thereon having a drop bottom door and latch means forholding the door closed, the combination of tripping mechanism mountedat the trackway and including a tripping member, means mounting thetripping member for upward swinging movement to engage the latch meansand for lowering movement in a direction forwardly of the trackway, anupright contact member adapted for engagement by means on theconveyance, a pivoted lever having the contact member slidably mountedthereon, a coiled spring interposed between the pivoted lever and thecontact member, a connecting arm, means operatively connecting thepivoted lever with the connecting arm, and a lost-motion springconnection between said connecting arm and the tripping arm.

5. In conveying mechanism, including a trackway adapted to receive adumping conveyance thereon having a drop bottom door and latch means forholding the door closed, the combination of tripping mechanism mountedat the trackway and including a tripping member, means mounting thetripping member for upward swinging movement to engage the latch meansand for lowering movement in a direction forwardly of the trackway, anupright contact member adapted for engagement by means on theconveyance, a pivoted lever having the contact member slidably mountedthereon, a

l coiled spring interposed between the pivoted lever and the contactmember, a connecting arm, means operatively connecting the pivoted leverwith the connecting arm, a coiled Spring interposed between theconnecting arm and the tripping arm, and adjustable stop means forlimiting the movement of the tripping arm in an upward direction.

6. A latch tripping device adapted to control the release of a dropbottom door supported by latch means on a dumping conveyance, comprisinga tripping member adapted to engage and release the latch means, meansmounting the tripping member for upward swinging movement in onedirection, a lever arm extending toward the tripping member, meansforming a resilient connection between one end of the lever arm and thetripping member, a pivotal support for the opposite end of the lever armfor upward swinging movement of the latter in the opposite directionfrom the tripping member, an actuated member operatively connected withthe lever arm, and a resilient support for the actuated member yieldablyholding the latter in position for engagement 2,225,463 with a portionof the conveyance for actuation thereby. 2,399,708 2,441,978

References Cited in the ie of this patent 2,487,447

UNITED STATES PATENTS Jones Feb. 23, 1915 8 Rose Dec. 17, 1940 SanfordMay 7, 1946 Sanford May 25, 1948 Kepner Nov. 8, 1949 Sanford July 14,1953

